Radial Force Control in Switched Reluctance Motors Using Strain Gauges

Switched reluctance motors offer various advantages such as having simple and robust structures, low manufacturing costs, high efficiency, and high torque density. However, the significant acoustic noise and vibration limit their application, such as in the traction motors of electric vehicles. The electromagnetic radial force acting on the stator is the main source of motor vibration. Shaping the radial force and reducing specific harmonic components is effective in reducing acoustic noise and vibration. Most force-shaping methods are based on finite element analysis, hence the differences between real machines and analysis models can reduce the effectiveness of these methods. In this paper, a novel approach for controlling the radial force online is proposed. In the proposed method, the radial forces are estimated by strain gauges. Simulation results showed that the estimated radial force waveform converged to the reference waveform in a switched reluctance motor. The proposed method was also validated in experiment where the reduction of vibration was confirmed.